Spring loaded coulter



Sept. 22, 1970 R. G. MOE ETAL SPRING LOADED COULTER Filed Oct. 20, 1967 United States Patent U.S. Cl. 172--572 4 Claims ABSTRACT OF THE DISCLOSURE To provide a rubber biasing spring for a rolling coulter assembly and wherein such spring will provide a high degree of ground penetration under adverse soil conditions, will occupy a minimum space thus affording good clearance and eliminating obstructions for trash to hang on. In addition, this construction is economical to manufacture.

The present invention is generally concerned with plow coulters. Field experience with this type of coulter equipped with a conventional steel wire torsion spring indicates that a very powerful spring is required to provide proper functioning under very difficult soil conditions. Increasing the size and altering the shape of the wire to obtain a greater down pressure has been tried and it has been found in order to provide adequate penetration it required a large wire spring which was very expensive and the increased overall size of the spring was restrictive from the standpoint of limiting its use where clearances were a problem and in addition the oversized spring presented a trash problem.

Accordingly, it is an object of this invention to provide a rolling coulter with a relatively small spring which provides a high degree of ground penetration under adverse ground conditions.

It is a further object of this invention to provide a rolling coulter with a spring which provides a high degree of ground penetration under adverse ground conditions and wherein such spring occupies relatively little space.

A further object of this invention is to provide a rolling coulter with a spring which provides such coulter with a high degree of penetration in adverse ground conditions, with such spring occupying little space and being relatively inexpensive.

A further object of this invention is to provide a rolling coulter with a resilient spring comprised of rubber or like material which while providing such coulter with a high degree of penetration in adverse ground conditions such spring occupies less space and costs less than a comparable steel spring.

Further objects and advantages will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawings, wherein an illustrative embodiment of the invention is shown. However, it is to be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention.

Referring to the drawings:

FIG. 1 is a side elevation of a spring mounted rolling coulter assembly; and

FIG. 2 is a plan view of the coulter shown in FIG. 1.

Referring to FIG. 1, the present invention is illustrated by means of a crank type shank 10 removably attached at its upper end to a support (not shown), a coulter disk 11 and a single arm 12 which rotatably supports the disk 11. Arm 12 is mounted by means of a casting or bracket 13 for limited horizontal movement and to swing in a vertical plane about a horizontal axis with biasing means Patented Sept. 22, 1970 "ice being provided to function as a desired spring loaded joint between the arm and the lower end of shank 10.

The upper end of coulter arm 12 is rigidly secured to a flat plate or support member 14 of the rubber spring assembly 18 by means of threaded studs 16 and nuts 17. It is to be noted that the studs 16 are an integral part of the spring assembly 15, and the flat plate 14 is offset outwardly around the stud heads to maintain a constant rubber body section and thereby assuring uniform operation. The flat plate 14 is attached as by vulcanizing to a resilient rubber block 18. Plate 14 is provided with end portions 14' formed to provide protection for the peripheral portion of the rubber block 18. The coulter arm 12 is provided with a rigid pin 19 which contacts either abutment or stops 20- or 21 of the pivot casting 13 to limit the vertical movement of arm 12 and prevent overstressing of the rubber spring 18. The pivot casting or bracket 13 is received about shank 10 for pivotal movement about the central vertical axis of shank 10 and bracket 13 is also provided with a pair of circumferentiab ly spaced abutments or stops 22 and 23 (see FIG. 2) which contact a boss 24 on a retaining collar 25 for limiting the horizontal pivotal movement of bracket 13. Collar 25 is held on the shank 10 by means of set screws 26.

Bracket 13 is pivotally retained on shank 10 as follows: The lower inner portion of bracket 13 is provided with an annular groove 27 (see FIG. 1) and shank 10 is provided with a transversely extending opening 28 positionable adjacent groove 27. Casting 13 is also provided with an opening 29 connecting with groove 27. A roll pin 30 is driven through opening 29, groove 27 transverse opening 28 and groove 27. Roll pin 30 being of a length equal to the outer diameter of groove 27 so that when pin 30 has been driven home, casting 13 can rotate relative to shank 10 but will not be removable without first removing roll pin 30.

A conical ring or support 31 (see FIG. 2) is vulcanized to the rubber block 18 and has a tubular pin 32 rigidly secured thereto, as by welding, with the pin 32, extending outwardly through a close fitting opening 33 providing a slip fit with the coulter arm 12. The opposite end of the pin 32 is received in a transverse opening 34 in pivot casting 13 and is rigidly secured therein by pin 35.

When a rock or other relative stationary obstacle is encountered which exerts a lateral force on the coulter, the blade 11 will swing laterally about the axis of the lower portion of shank 10 until one of the abutments 22 or 23 is contacted with any further lateral loads being transmitted to the coulter shank 10 through the pin 32 by virtue of the close fitting pilot extension of the pin 32 through the coulter arm 12. This prevents these lateral forces from being transmitted through the rubber spring 15 thereby protecting it against damage.

When a rock or the like is struck by coulter blade 11 this tends to raise or pivot blade 11 about the longitudinal axis of tubular pin 32. This pivotal movement of blade 11 is yieldingly resisted by rubber torsion spring 15 until blade 11 raises to the point that pin 19 on arm 12 contacts stop member 21. Stop member 21 prevents further movement of arm 12 and thereby eliminates overstressing of spring 15. A lower stop member 20 is provided so that spring 15 may be provided with some initial preload.

In summation, the purpose of the present invention is to provide a resilient spring of rubber or like material for a vertically biased rolling coulter which spring is lower in cost and takes up less space than a comparable steel wire torsion spring, and wherein such spring is capable of being operated in two directions whereas a steel coil spring would require left and right hand parts to provide such functioning.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A coulter construction comprising a vertical shank adjustably and detachably mounted on a traveling support, said shank having a mounting portion at a lower end thereof, a bracket rotatably secured to said mounting portion for limited movement in a horizontal plane, an arm having a ground working coulter on one end thereof, means pivotally mounting the other end of said arm on said bracket for limited movement in a vertical plane, said means including a pair of spaced apart support members rigidly associated with said arm and said bracket, one of said support members being attached to said arm and the other support member being attached to said bracket, a block of rubber having opposite sides vulcanized to said support members for yieldingly resisting movement of said arm in a vertical plane, and additional means for preventing lateral movement of said arm relative to said bracket, said additional means including a transversely extending pin pivotally received in said arm, said one support member and said 'block of rubber, and said pin being rigidly attached to the other of said support members and said bracket.

2. A coulter construction as recited in claim 1 and wherein a slip fit is provided between said pin and said .4 arm so that the reaction to lateral movement of said coulter is transmitted directly from said arm to said pin. 3. A coulter construction as recited in claim 1 and wherein a retaining collar is attached to said shank for preventing vertical movement of said bracket relative to said shank and stop members are provided in circumferentially spaced apart relation on said bracket and coacting with a boss carried by said collar for limiting the rotation of said bracket in either horizontal direction. 4. A coulter construction as recited in claim 1 and wherein stop means are provided including a laterally extending mem'ber carried by a midportion of said arm coacting with vertically spaced portions of said bracket for limiting vertical swinging movement of said arm.

References Cited UNITED STATES PATENTS 1,427,649 8/ 1922 Silver 172602 2,981,537 4/1961 Roe 26757.1 3,405,767 10/1968 Thomson 172572 3,411,589 11/1968 Moe 172572 ROBERT E. PULFREY, Primary Examiner S. C. PELLEGRINO, Assistant Examiner US. Cl. X.R. 

